According to a particle beam therapy system, high energy charged particles which are accelerated by an accelerator such as a synchrotron are extracted from the accelerator as a particle beam having a beam shape, the particle beam which is extracted is transported to a treatment chamber by a particle beam transport section comprising vacuum ducts, deflection electromagnets, etc. so as to irradiate the particle beam to an affected part of a patient by a particle beam irradiation device.
Regarding a particle beam therapy system, it is necessary to arrange an accelerator, a transport section and a treatment chamber, therefore a relatively large area is needed. In order to reduce installation area, the configuration in which a treatment chamber is arranged at a site whose height is different from that of an accelerator, that is, a treatment chamber is arranged on a floor which is different from that on which an accelerator is arranged is proposed (for example, Patent Document 1, Non-patent document 1).
In Patent Document 1, a particle beam irradiation system has the configuration in which a cyclotron is used as an accelerator, a treatment chamber is arranged directly above an accelerator installation chamber, a particle beam which is emitted from the accelerator is transported to a treatment chamber by a deflection electromagnet for perpendicularly deflecting a particle beam. Further, two treatment chambers are provided, gantry type irradiation devices are arranged radially at each treatment chamber. Switching of particle beam to the two irradiation devices are realized by a mechanism for rotating an electromagnet.
On the other hand, in Non-patent document 1, a particle beam irradiation system has the configuration in which a synchrotron is used as an accelerator, in the same way as that of Patent Document 1, a treatment chamber is arranged directly above an accelerator installation chamber, a particle beam which is extracted from the accelerator is transported to a floor where a treatment chamber is arranged by a deflection electromagnet for perpendicularly deflecting the particle beam and on the floor where a treatment chamber is arranged, the particle beam is further deflected by a deflection electromagnet for horizontally deflecting the particle beam so as to transport to the treatment chamber. In a treatment chamber, a gantry type irradiation device is arranged.